On my recently purchaced 92 rs (engine swaped to 5.7 by the previous owner) everything was great until I went to start it today for work..
When I turn the key it has power to everything but when I complete the turn to ignition it drops all power.
If I turn the key back the power comes back.

About every 30 or so turns it may crank over but will only run for a few moments.

I am sure it had vats at some point in time but the column has been broken and the old cylinder removed and replaced.

I have had the car for months using it every day with zero problems,anybody have an idea what I may be dealing with here.

Thanks

 

You either don't have enough power in the battery or a big power drain ( faulty starter?) when trying to start
What volts are showing before and during cranking?
How good is the battery?
How old ?
Fully charged?
Does your Alt work correctly and charge the batt?

VATS only takes out the starter ( and fuel injectors ) , would have no effect on anything else

 

Thanks Vetteoz -

Before Cranking voltage shows dead center- during it drops to about a quarter

Battery is 2 years old and on testing it shows that it does not hold a full charge.

Alternator tests good.

There is a ton of hokey wiring that has been done on this car due to the motor swap i assume so there could be something draining.

I am changing out the ignition switch(what a pain) and wiring that back to how it should be. Then I am going to set sights on wiring the fans properly. After that I will slap in the new battery and cross my fingers.

Thanks for the help

 

You can't do any meaningful diagnosis with an iffy battery.

 

Well turns out it was the ignition switch, after getting the old switch off it had three burned out pins. Replaced the switch,rewired back to specs and reassembled.
She fired right up stronger than ever.

Started on the hokey fan wiring and discovered that it was not grounded!!
For now I am going with the manual switch (now grounded) but I plan to wire that back to spec this weekend. Looking at the diagrams for it on here I dont understand why someone would wire it like this? Very simple to just do properly!

Thanks for the help